Do not “copy and paste” the bootargs= line in your terminal program thinking that you will just modify it … at least with minicom the line was executed immediately, which then resulted in a kernel panic on the next boot Also, double-check your intended modification to ensure you have got it correct!

If you mess this up, reboot the NanoPi and within 3 seconds stop the boot process and do a printenv, in your terminal window, to see where you went wrong.

Hi all,I own a nanopi and I intend to use in a standalone environment where it is powered by a battery pack. In order to save power consumption I want to put the device in standby mode and once an hour it needs to wake up. It should do than some measurements, save it to SD and go again to enjoy some sleeping time. However, rtcwake does not seem to be supported. The utility is available but not working:rtcwake -m standby -s 60 ===> says rtcwake: suspend to "standby" unavailablertcwake -m mem -s 60 says===>rtcwake: wakeup from "mem" using /dev/rtc0 at Thu Jan 1 12:56:40 2015 rtcwake: write error.

Any help from you guys. Is there a different approach I should be using to achieve my goal?Thanks in advance.

Hi Sorry this function might not be supported in NanoPi. In order for this function to be supported uboot, kernel and hardware all need to be configured and setup. The hardware doesn't support this function and we didn't specifically test the uboot and kernel for this function either.

When I first started looking at the NanoPi I recall that there was a RTC timer. However, being used to externally battery-backup RTCs I came to the conclusion, perhaps incorrectly, was how was running this off the main 5V supply and without a PMU going to reduce current consumption.

Also, I would like to change my NanoPi2 Fire statement to "maybe an external RTC is NOT required".

davef,you're a star. Thanks a lot. you pushed me in the right direction.I was able to switch off the WiFi and I would expect power consumption will dramatically decrease.I will do some testing to figure out what the power consumption is in both scenarios (with and without WiFi). Thanks again

Hi davef,I followed your instructions as I was able to switch off the WiFi.I then did some dirty measurements trying to figure out what the power consumption is. This what I did:I created a small python script that writes the current time to a file on the SD card, each 5 minutes. I used a power bank of 2200 mAh and 5V (fully charged) to power the nanopi. After a while the battery runs out and the nanopi stops working:- Having WiFi on, nanopi needed 7:15 h to drain out the power bank.- Switching off the Wifi same power bank took 11 h to drain out.

So switching off the WiFi has resulted in a better improvement, but still I would like to bring the power consumption down as the nanopi will only need to take some measurements store them om SD and go back to sleep for another hour.

davef,You asked lately if I have to use Linux. Is there any other OS i can use to save more power?Thanks